(a) Field of the Invention
The present invention relates to a demultiplexing device and a display device using the same. More specifically, the present invention relates to a demultiplexing device for demultiplexing current using a sample/hold circuit.
(b) Description of the Related Art
A display device requires a gate drive integrated circuit (IC) for driving scan lines and a data drive IC for driving data lines. The data drive IC has output terminals corresponding to the number of data lines since it converts digital signals into analog signals and applies the analog signals to all the data lines. A plurality of data drive ICs are used to drive all the data lines since the number of output terminals on a single IC is limited. Hence, demultiplexers are adopted so as to reduce the number of data drive ICs.
For example, a 1:2 demultiplexer receives data signals time-divided and applied by the data drive IC through a signal line, divides them into two data groups, and outputs them to two data lines. Therefore, usage of a 1:2 demultiplexer reduces the number of data drive ICs by half. Recent liquid crystal displays (LCDs) and organic electroluminescent displays are beginning to mount the data drive ICs on the panel, and in this instance, there is a greater need to reduce the number of data drive ICs.
Analog switches are used to configure a demultiplexer. For example, in the case of a 1:2 demultiplexer, two analog switches are coupled between a signal line of the data drive IC and two data lines, and the analog switches are alternately turned on to alternately transmit the data signals time-divided and applied through the signal line to the two data lines. The organic electroluminescent display uses the method of programming data using current in order to program the data on the pixels. When using the analog switches, the time for applying the data current to a data line is half the horizontal period. Therefore, the data current is insufficiently programmed to the pixels since the time for programming the data on the pixels is reduced as compared to using no demultiplexer.